The invention relates to a device for the vertical adjustment of the upper anchorage or deflection point of a safety belt system as a function of the longitudinal position of an associated motor vehicle seat.
In known automatic adjustment devices of this generic kind, a stepped-down but linear displacement of the upper anchorage or deflection point is provided over the entire displacement path of the vehicle seat, with the result that, in the case of seats which can be adjusted rearward a long way, the anchorage or deflection point may be driven into an excessively high position in relation to the size of the body of the belt user, which cannot be made to suit people with a short upper body in particular, and can even become dangerous.
It is an object of the present invention, while retaining the advantages offered by a design of the upper belt anchorage or belt deflection point which is vertically displaceable as a function of the longitudinal position of the seat, to provide a device which permits a vertical position of the belt anchorage or belt deflection point which takes into account the physical realities of the seat user, even with the seat pushed back a long way.
The object is achieved in a device according to the invention, in which the longitudinal position of the seat is transmitted, with deflection, via a cable guided in a sheath and coupled to a slider vertically displaceable in a guide rail between a lower and an upper stop and accommodating an attachment fitting or sash guide. The vertical position of the upper stop is advantageously determined specifically for the particular vehicle. Moreover, it is also possible to cause the upper stop to move further upwards by a specific small amount after the slider has run up against it, in the event of the seat being displaced further rearward, with the result that (for example) a bilinear adjustment function is achieved, which is also achievable in the case of the subject-matter of German Patent document DE-OS 3,539,399 using other means.
Although German Patent document DE-OS 3,713,137 discloses a vertically adjustable belt deflection point in which a cable displacement directed counter to spring force is permitted in the case of a certain load condition, such condition occurs when, in the case of danger, belt tightening is required to bring about a locking engagement of the belt adjustment device in any fixed position of the seat.
In a preferred illustrative embodiment of the present invention, which can be implemented easily, the arrangement comprises a cable pulley at least partially wrapped by the cable and the latter has a guiding groove into which a guide projecting at the top of the slider engages before the upper stop formed by a wall of the guiding groove is reached. Unlocking of the cable pulley is brought about by the guide, so that, in the event of a further rearward displacement of the motor vehicle seat, rotary movement of the cable pulley and withdrawal of the cable are permitted, and the guide slides in the guiding groove, with at least substantial retention of the vertical position of its upper attachment or deflection point.
In a further embodiment of the invention, the unlocking of the cable pulley is brought about via a spring-loaded, two-armed bent lever which is mounted on the guide rail, one arm of which can be acted upon by the guide causing the other arm to be lifted out of a notch of the cable pulley.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.